Junctionless ophthalmic lenses and methods for making same

ABSTRACT

Methods for producing a junctionless ophthalmic lens are provided. Additionally, ophthalmic lenses having junctionless, three dimensional surfaces, for example, asymmetrical anterior and/or posterior surfaces, as well as molding tools used in the production of such lenses, are also provided. The method generally include providing sample data points to define a surface contour, and interpolating between these data points using an algorithm to produce a simulated three dimensional surface. The simulated three dimensional surface is used in producing an ophthalmic lens, for example, in cast molding a contact lens.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of application Ser.No. 09/709,132, filed Nov. 10, 2000, the disclosure of which in itsentirety is hereby incorporated by reference.

[0002] The present invention generally relates to ophthalmic lens designand more specifically relates to junctionless ophthalmic lenses andmethods for manufacturing ophthalmic lenses having junctionless, threedimensional surfaces.

[0003] Contact lens design typically involves a number of steps. Theback surface, i.e. posterior surface, of the lens is frequently designedfirst based on the shape of the cornea and a desired cornea-lens fittingrelationship. The front surface, i.e. anterior surface, of the lens isconstructed to obtain the necessary refractive correction for the eyeand the desired lens performance. Such performance depends on a numberof factors, including, but not limited to, lens mass distribution toprovide effective eyelid interaction to achieve desired lens movementand lens position, other configurational considerations to provide forthe comfort of the lens wearer and the like.

[0004] It is known that the surface topographies of a normal humancornea are often not spherical. For example, it is well known that thecorneal surface of an eye has a curve that generally flattens from thecenter of the cornea to the periphery. A typical approach to create aflatter peripheral lens surface and adequate edge clearance between theedge of the lens and the underlying cornea/conjunctiva, has been togenerate a series of conic section curves, each having a radius ofcurvature larger (i.e. flatter) than the preceding one. Both theanterior and posterior surfaces of conventional contact lens designshave been described in two dimensions by a series of rotationallysymmetric surface segments. The surface segments may or may not beoffset from the axis of symmetry.

[0005] Conventionally designed lenses have been therefor described intwo dimensions, such as by a series of rotationally symmetric surfacesegments, and may be mathematically described thereby. The mathematicaldescriptions of two dimensional surface sections are made smooth andcontinuous by compositing, for example, splines or polynomials orblending of the sections. Such smooth, continuous surfaces can beconsidered to be free of junctions, or junctionless. Thus, ophthalmiclens surfaces with junctions have segments which intersect atdiscontinuities which can cause discomfort and/or one or more otherreductions in lens performance. Thus, it is advantageous to provide anophthalmic lens with one or more substantially junctionless surfaces.

[0006] Ducharme U.S. Pat. No. 5,452,031, which is incorporated in itsentirety herein by reference, discloses a contact lens and method formanufacturing a contact lens having a smooth, junctionless surface. Morespecifically, the Ducharme patent discloses a method for defining theshape of the contact lens surface by relating the corneal surface to areference curve. The reference curve may be derived from the use ofpiecewise polynomials and splines, based on point coordinates, resultingin a junctionless surface topography. A computer controlled lathereceives the spline data and generates a signal indicating the necessarylens form to be cut.

[0007] Vayntraub U.S. Pat. No. 5,815,237 which is incorporated in itsentirety herein by reference, discloses a method for making a contactlens having a peripheral zone surface defined by an exponentialfunction. Similarly, Vayntraub U.S. Pat. No. 5,815,236 and alsoincorporated in its entirety herein by reference, discloses a method formaking a contact lens having a peripheral zone surface defined by alogarithmic function.

[0008] Although more closely approximating the curvature of a human eyethan earlier spherically based contact lens forms, these nowconventional lens computer aided design methods, which are based onusing polynomial and spline based interpolations, or exponential andlogarithmic mathematical functions, result in a lens constrained to atwo dimensional description of the surface topography.

[0009] The surface topography of a normal human cornea is often uniqueand includes areas of irregularity, asymmetry and asphericity that cannot adequately be described in two dimensions. Likewise the lensanterior or posterior lens surface shape required to achieve optimallens performance cannot be adequately described in two dimensions.Particularly in such cases, conventional two dimensional computer aidedlens design methods are insufficient.

[0010] Designing a lens in two dimensions is inadequate when one or moreof the posterior or anterior surfaces involves an asymmetric component,that is a rotationally asymmetric component. Although computercontrolled manufacturing techniques have facilitated manufacture oflenses in recent years, such techniques in practice have had onlylimited application and are inadequate in design and production oflenses having one or more asymmetric components, particularly lenses foruse in or on an eye, such as contact lenses, intraocular lenses andcorneal onlay lenses. This is because current art in lens designnecessarily requires assumptions and compromises to the design by theaveraging and compositing of many two dimensional surfaces. Suchassumptions and compromises can result in reduced lens performance, bothoptically and based on user comfort.

[0011] It would be advantageous to provide new ophthalmic lenses andmethods of designing and producing ophthalmic lenses which address oneor more of the concerns with prior lenses, lens designs and productionmethods.

SUMMARY OF THE INVENTION

[0012] New ophthalmic lenses and methods for ophthalmic lens design andmanufacture have been discovered. The present lenses and methods offersignificant advantages over conventional lenses and methods by providingophthalmic lenses having substantially smooth, junctionless, threedimensional surfaces which may include one or more rotationallyasymmetric components. Lenses produced by the methods in accordance withthe invention may include, but are not limited to, ophthalmic lensesstructured and adapted for use in or on an eye, for example, all typesof contact lenses, such as toric contact lenses, monofocal andmultifocal contact lenses and the like, intraocular lenses (IOLs), suchas anterior chamber IOLs, posterior chamber IOLs and the like, cornealonlay lenses, such as lenses affixed on the cornea, lenses placed oraffixed in the cornea and the like. In addition, methods of the presentinvention may be utilized during corneal refractive laser surgery, forexample in the shaping of the cornea.

[0013] The present invention provides methods for designing andmanufacturing ophthalmic lenses having one or more substantially smooth,junctionless, three dimensional surfaces, for example, wherein thesurface or surfaces may have one or more asymmetrical components. Thescope of the present invention also includes such lenses, toolinginserts and mold sections used to manufacture such lenses, and methodsof producing such tooling inserts and mold sections.

[0014] Advantageously, the present invention provides one or moreadditional, for example, relative to the prior art, degrees of freedomto control lens shape, surface contour, distribution of mass, opticalpower location and the like parameters within the lens design.Consequently, enhanced ophthalmic lens performance, for example, relatedto comfort, fitting, vision and/or lens positioning are provided by thepresent invention.

[0015] It will be appreciated that the present methods are especiallyadvantageous when applied to lens design where constraints of symmetrywould otherwise present a disadvantage. For example, the methods arevery well suited for the design of toric contact lenses, for example atoric contact lens including a posterior toric optical zone and ananterior surface shaped to provide the lens with appropriate opticalpower and a thickness profile facilitating lens orientation andstabilization in the form of a ballast.

[0016] Moreover, the present invention provides for enhancedreproducibility of the ophthalmic lens dimensions and surfaces. Thepresent invention very effectively complements modern CNC lathes whichhave been used to produce ophthalmic lenses.

[0017] In one broad aspect of the present invention, methods forproducing ophthalmic lenses are provided which generally compriseproviding or specifying selected sample data points from a designatedsurface, for example, a designated corneal surface (the surface of thecornea of the wearer of the lens) or designated or desired anterior lenssurface, interpolating between the sample data points using at least onealgorithm to define a simulated three dimensional designated surface,preferably that has a relationship to, for example, is based at least inpart on, the designated surface, and forming an ophthalmic lens havingthe simulated three dimensional designated surface. The simulated designsurface preferably is sufficiently well defined, for example, in theinterpolating step, to be a smooth, substantially junctionless threedimensional surface. In one embodiment, the simulated three dimensionalsurface is defined, during the interpolating step, using the sample datapoints and one or more factors or relationships for one or more lensdesign parameters. Advantageously, the forming step is conducted so thatthe ophthalmic lens has the desired lens design parameters including,but not limited to, the desired optical correction or corrections, size,configuration, space or gap between the cornea and posterior surface ofthe lens and other desired optical fitting relationships and the like.

[0018] Advantageously, the methods of the present invention can be usedto produce contact lenses having surfaces not constrained to contoursdefined by a two dimensional surface of rotation. Rather, the presentlenses preferably are defined by one or more smooth, substantiallyjunctionless, three dimensional surfaces, including any rotationallyasymmetric components unique or customized to the wearer's eye. Thisresults in an improved lens/cornea fitting relationship and/or anteriorsurface shape that achieve desired physical, physiological lens movementand/or vision correction objectives.

[0019] In one aspect of the invention, ophthalmic lenses are providedand comprise lens bodies, preferably structured and adapted to belocated in or on an eye, having anterior surfaces and generally opposingposterior surfaces. At least one of the anterior surface and theposterior surface is a substantially smooth, junctionless, threedimensional surface. The junctionless surface may be an asymmetricalsurface. In certain embodiments, the ophthalmic lens has a variedanterior surface topography defining a ballast. Such a varied anteriorsurface topography may, and preferably does, facilitate at least one oflens comfort, lens orientation, vertical lens translation, and/or lensstabilization when the lens is located on a corneal surface. Inaddition, the lenses may have a lens body with at least one contour thatdefines a substantially junctionless varying radial thickness. Suchophthalmic lenses may include hydrophilic silicone polymer components,and in particular embodiments, the ophthalmic lenses include siliconehydrogels. In situations where the ophthalmic lens is used to providevision correction for an astigmatism, the lens may, and preferably does,include a toric surface, such as a toric posterior surface. Insituations where more than one optical power is necessary to provide adesired vision correction, the lens may, and preferably does, include amulti-powered optical zone. In other words, the lens may include amulti-focal optical zone (e.g., an optical zone having two or moreoptical powers). Accordingly, multi-focal lenses may include bifocallenses, trifocal lenses, and the like.

[0020] In another aspect of the present invention, a contact lens isprovided which includes a lens body containing a hydrophilic siliconepolymer component, such as a silicone hydrogel and the like. The lensbody may be shaped or formed in accordance with the methods disclosedherein. These contact lenses may include a toric surface, such as forproviding vision correction to astigmatic eyes, and may include a variedsurface topography with at least one contour that defines asubstantially junctionless varying radial thickness, and facilitates atleast one of lens comfort, lens orientation, vertical lens translation,and/or lens stabilization when the contact lens is placed on a cornealsurface of an eye, for example, a living human eye.

[0021] In a further aspect of the present invention, a contact lens isprovided which comprises a lens body including a silicone hydrogel andhaving a varied surface topography with at least one contour thatdefines a substantially junctionless varying radial thickness of thecontact lens. Such varied surface topography may, and preferably does,facilitate at least one of lens comfort, lens orientation, vertical lenstranslation, and/or lens stabilization when the lens is placed on acorneal surface of an eye. The lens may include a toric surface

[0022] Although, for illustrative purposes, the description of thepresent invention set forth herein emphasizes contact lenses and methodsrelating to contact lenses, it is to be understood that the presentinvention is adapted to ophthalmic lenses in general, and preferably toophthalmic lenses structured and adapted to be located in or on an eye,and to methods relating to such ophthalmic lenses. All such lenses andmethods are included within the scope of the present invention.

[0023] The present invention may be adapted for use in producingophthalmic lenses using any suitable processing technique or combinationthereof. In one useful embodiment, the present invention is utilized inconjunction with conventional cast molding techniques, for example inthe initial design of a tooling insert having a surface generallycorresponding to a desired lens surface. As is well known to thoseskilled in the art, a tooling insert, or tool, is used to form a moldsection which generally defines a negative impression of a surface of afinal lens product.

[0024] For example, a tooling insert having a three dimensional,substantially junctionless surface designed by a method of theinvention, is positioned in a molding apparatus, such as a moldingapparatus of conventional design. A moldable composition, such as apolymeric material or a composition of a polymeric material, isintroduced into the molding apparatus and subjected to conditionseffective to form a mold section having a negative impression of thesurface of the tool. The mold section formed by the tool may be either aback surface mold section, or a front surface mold section dependingupon the tooling insert design. In other words, the surface of the toolgenerally corresponds to a face, either a posterior or an anterior faceof the ophthalmic lens to be formed.

[0025] As is conventional, the mold section is assembled with acomplementary mold section to form a lens-shaped cavity therebetween. Acontact lens precursor material is introduced into the lens-shapedcavity. Upon demolding or removal from the mold sections, a lens productis obtained. As is typical, post formation processing steps may beemployed to the demolded contact lens product. These steps may includehydration, sterilization, packaging and the like. These steps are wellknown and are not considered part of the present invention.

[0026] In accordance with the present invention, the tooling insert mayinclude irregular or asymmetric surface contours that are customized orunique to the wearer's eye, or contours which are not definable as asubstantially junctionless surface by a two dimensional curve orinterpolation. The design of the tooling insert preferably isaccomplished by a method comprising providing or specifying sample datapoints from a designated, three dimensional surface, for example, adesignated corneal surface or a designated or desired anterior lenssurface, interpolating between the data points using at least onealgorithm to define a simulated three dimensional designated surface,and forming the simulated three dimensional surface on the toolinginsert, for example, on a tooling insert blank.

[0027] In this embodiment of the invention, cast molded ophthalmiclenses, for example, contact lenses, are made having improved fit,and/or anterior surface shape and/or vision correction performanceand/or other performance relative to conventional or prior art castmolded lenses, for example, that are conventionally produced usingsymmetric, conic or spherical inserts.

[0028] Alternative lens manufacturing techniques may be used inconjunction with the methods of the present invention. For example, thealgorithm may be used in conjunction with lens surface forming tools,including but not limited to lathes or mills. The simulated designatedthree dimensional surface can be cut directly onto a lens blank, forexample, using a computer driven surface cutting tool.

[0029] In another aspect of the present invention, methods for reshapingcorneas are provided. Such methods comprise providing or specifyingsample data points from a three dimensional corrected corneal surface,that is a corneal surface to be provided to the cornea of a patient toobtain a desired result, such as a desired vision correction;interpolating between the sample data points using at least onealgorithm to produce a smooth, substantially junctionless, simulatedthree dimensional surface; and providing an optical correction to acornea by shaping the surface of the cornea to approximate the simulatedthree dimensional surface. In one useful embodiment, the methods furthercomprise providing sample data points from a three dimensional surfaceof the uncorrected surface of the cornea of the patient; andinterpolating between the sample data points using at least onealgorithm to produce a smooth, substantially junctionless, simulatedthree dimensional uncorrected surface, which is then employed in theproviding step.

[0030] The present methods are effective to determine what degree ofcorneal reshaping is required to achieve a desired vision correction.The simulated three dimensional corrected corneal surface is the surfacewhich will provide the desired correction, for example, visioncorrection. The uncorrected surface that is interpolated from the sampledata points of the uncorrected cornea represents the surface of thecornea prior to reshaping. Thus, the degree of reshaping required to gofrom the original, uncorrected shape of the cornea to the desired orcorrected shape of the cornea for a desired correction is determined.

[0031] The reshaping itself can be performed using any. suitable methodwhich can be adapted to be controlled in accordance with the presentinvention. In one particularly useful embodiment, the step of providinga correction includes ablating the surface of the cornea using acomputer-driven laser system, such as is conventionally used inreshaping corneal surfaces. The step of providing a correction mayinclude producing an asymmetrical surface on a corneal surface, forexample, on a symmetrical corneal surface.

[0032] Each and every feature described herein, and each and everycombination of two or more of such features, is included within thescope of the present invention provided that the features included insuch a combination are not mutually inconsistent.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The advantages of the present invention will be more readilyunderstood with reference to the following description when consideredin conjunction with the appended drawing of which:

[0034]FIG. 1 shows a simplified, cross sectional representation of acontact lens on an eye surface;

[0035]FIGS. 2a, 2 b and 2 c show, respectively, a front viewrepresentation including thickness data, a nominal radial thicknessprofile for a horizontal cross-section through the lens center and aside view of a rotationally symmetric, spherical contact lens designedin accordance with a method of the present invention. The regionsbounded by broken lines (2 a) designate transition regions betweenadjacent areas of substantially different surface types.

[0036]FIGS. 3a, 3 b and 3 c show, respectively, a front viewrepresentation including thickness data, a nominal radial thicknessprofile for a horizontal cross-section through the lens center and aside view of a rotationally asymmetric, toric contact lens designed inaccordance with a method of the present invention. The regions boundedby broken lines (3 a) designate transition regions between adjacentareas of substantially different surface types.

[0037]FIG. 4 shows a front view representation, a cross-sectional viewincluding thickness data of a complex design contact lens designed inaccordance with a method of the present invention. The regions boundedby broken lines designate transition regions between adjacent areas ofsubstantially different surface types.

[0038]FIGS. 5a and 5 b show three dimensional representations of,respectively, a rear surface/cornea separation (α) and a radialthickness (δ) profile for the radially symmetric lens of FIGS. 2a-2 c;

[0039]FIGS. 6a and 6 b show three dimensional representations of,respectively, a rear surface/cornea separation (α) and a radialthickness (δ) profile for the toric lens of FIGS. 3a-3 c; and

[0040]FIG. 7a and 7 b show three dimensional representations of,respectively, a rear surface/cornea separation (α) and a radialthickness (δ) profile for the complex design lens of FIG. 4.

[0041]FIG. 8 is a schematic diagram illustrating one method forproducing lenses in accordance with the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0042] The present invention is directed to ophthalmic lenses andmethods for designing and producing such lenses, including but notlimited to monofocal, multifocal and toric contact lenses, intraocularlenses, corneal inlay lenses and other ophthalmic lenses.

[0043] It has been discovered that the methods of manufacturingophthalmic lenses in accordance with the present invention areparticularly advantageous with lenses made from a hydrophilic lensmaterials, including, but not limited to, hydrophilic silicone polymercomponents and the like, and mixtures thereof.

[0044] In reference to the disclosure herein, a polymeric hydrogelincludes a hydrogel-forming polymer, such as a water swellable polymer.The hydrogel itself includes such a polymer swollen with water.Polymeric hydrogels useful as ophthalmic lenses, for example, contactlenses, typically have about 30% to about 80% by weight water, but mayhave about 20% and about 90% by weight water, and have refractiveindices between about 1.3 and about 1.5, for example about 1.4. Examplesof suitable hydrogel-forming polymer materials or components of thedisclosed lenses include, without limitation, poly(2-hydroxyethylmethacrylate) PHEMA, poly(glycerol methacrylate) PGMA, polyelectrolytematerials, polyethylene oxide, polyvinyl alcohol, polydioxaline,poly(acrylic acid), poly(acrylamide), poly(N-vinyl pyrilidone) and thelike and mixtures thereof. Many of such materials are publiclyavailable. In addition, one or more monomers which do not themselvesproduce homopolymers which are hydrogel-forming polymers, such asmethylmethacrylate (MMA), other methacrylates, acrylates and the likeand mixtures thereof, can also be included in such hydrogel-formingpolymer materials provided that the presence of units from such monomersdoes not interfere with the desired formation of a polymeric hydrogel.

[0045] Ophthalmic lenses in accordance with the present invention mayalso be manufactured from a biocompatible, non-hydrogel material orcomponent. Examples of non-hydrogel materials include, and are notlimited to, acrylic polymers, polyolefins, fluoropolymers, silicones,styrenic polymers, vinyl polymers, polyesters, polyurethanes,polycarbonates, cellulosics, proteins including collagen-based materialsand the like and mixtures thereof.

[0046] Preferably, the lenses in accordance with this invention arehydrophilic. Hydrophilic lenses may be constructed from one or moremonomeric unit components, i.e., monomeric components. For example, andwithout limitation, the monomeric unit component may comprisehydrophilic monomers which provide —OH, —COOH, —NCO(CH₂)₃ (e.g.,pyrrolidone) and the like groups. Examples of useful hydrophilicmonomeric components include, without limitation, hydroxyalkylmethacrylates, such as hydroxyethyl methacrylate, methacrylic acidN-vinylpyrrolidone, acrylamide, alkyl acrylamides, vinyl alcohol,monomers, such as hydrophilic (meth)acrylates and the like and mixturesthereof, useful for inclusion in hydrophilic silicone polymericmaterials, e.g., silicone hydrogels, silicon-containing monomers forpolymerization into hydrophilic silicone polymers, siloxanes, such asorganosiloxanes and the like and mixtures thereof, silicon-containingacrylates, silicon-containing methacrylates, and the like and mixturesthereof. Preferably, the lens is a hydrogel-containing lens, morepreferably a silicone hydrogel-containing lens.

[0047] For the sake of simplicity and illustrative clarity, thefollowing detailed description will be directed primarily to the designof contact lenses. It will be appreciated by persons of ordinary skillin the art that the methods in accordance with the invention, possiblywith one or more appropriate modifications thereto, can be utilized inthe design of these and other types of lenses.

[0048] In accordance with a method of the invention, an ophthalmic lensis designed using a mathematical algorithm and a limited number ofspecifications to achieve a single, continuous, non-compositingmathematical surface in three dimensional space.

[0049] More particularly, after a corneal shape is determined for apopulation or a selected patient, a posterior surface of a contact lensis designed by interpolating between sample scattered data points usinga mathematical algorithm, preferably including relationships directed toone or more parameters desired for the resulting lens to have, forexample, the space or gap between the cornea and the posterior surfaceof the lens, as described elsewhere herein, to produce a simulated threedimensional surface (posterior lens surface), for example, that is basedat least in part on the corneal shape, such as closely approximating oneor more of the varying curvatures of the cornea. In certain embodiments,the lenses are formed to have a posterior surface that corresponds tothe surface topography of a cornea, such that a substantially uniformdistance is maintained between the posterior surface of the lens and thecornea. By reducing variations in distance between the lens and thecornea, enhanced lens fit and/or lens wearer comfort are obtained.Thickness data as well as specifications or relationships or for one ormore lens performance requirements or parameters, as described elsewhereherein, are provided and, in conjunction with the selected mathematicalalgorithm, define a three dimensional surface (anterior lens surface)having a desired thickness profile.

[0050] The simulated three dimensional surfaces can be formed onto alens using conventional manufacturing techniques, for example by castmolding techniques. Moreover, the present invention complements the useof modern CNC lathes.

[0051] By using this approach as detailed herein, anterior and/orposterior lens surfaces can be designed, preferably without substantialcompromise.

[0052] Referring now to FIG. 1, a simplified, vertical cross sectionalview of a contact lens 10 and cornea 12 is shown, taken across x and zcoordinate axes, with the y-axis being directed into the page. The lens10 includes a back surface (i.e. posterior surface) 14, that istangential to the x and y axes at (0,0,0). The cornea 12 lies a distanceα mm below a center of the back surface 14 of the lens 10, and a frontsurface (i.e. anterior surface) 18 lies a distance δ mm above the cornea12. The cornea has a surface 22 that is ellipsoidal with semi-axiallengths R₀ and R₁, as further described herein.

[0053] Any contact lens can be designed using the present invention.However, as indicated herein, it has been found that lenses comprisingone or more hydrophilic silicone polymer components particularly benefitfrom the methods disclosed herein. For example, contact lenses, such ascontact lenses containing silicone hydrogel components, in accordancewith the present invention which have a varying surface topographyeffectively facilitate at least one of enhanced lens comfort, enhancedlens orientation, enhanced vertical lens translation, and/or enhancedlens stabilization when placed on a corneal surface. Obtaining one ormore of such enhancements with lenses containing silicone hydrogels isparticularly useful since such lenses may be used for extended wear,e.g., used in the eye for at least about 1 week or about 2 weeks toabout 1 month or more without being removed. Lenses including one ormore features of the present invention are particularly useful asextended wear lenses. Such contact lenses include toric contact lensesor multifocal lenses. Thus, substantial benefits, for example, in termsof comfort, orientation, and stabilization, among other things, areobtained with the lenses of the present invention. This is particularlyimportant since lenses which comprise a hydrophilic silicone polymercomponent typically have a high modulus relative to other hydrogellenses.

[0054] In addition, a lens of the present invention may have a lens bodywith a portion or portions that are relatively thicker than otherportions of the lens body. For example, a lens body may have an inferiorportion that is thicker than a superior portion. Or, a lens body mayinclude a plurality of protrusions extending from a surface, such as theanterior surface of the lens body, which result in a greater thicknessat those protrusions than the remaining portions of the lens body. Suchthickened portions may be particularly useful in toric lenses, and/ormultifocal lenses that provide enhanced vertical lens translation. Thus,for example, with extended wear contact lenses, the silicone hydrogellenses with thickened regions advantageously provide enhanced gaspermeability relative to non-silicone hydrogel lenses. The siliconehydrogel lenses typically have enhanced oxygen and carbon dioxidepermeability, relative to other (non-silicon-containing) hydrogellenses.

[0055] For example, turning now to FIGS. 2a-2 c, a rotationallysymmetric, single vision contact lens 30 is shown, to represent one ofthe most simplest contact lens designs.

[0056] The present invention is particularly advantageous in the designand production of more complex, rotationally asymmetric lenses. Forexample, FIGS. 3a-3 c show a toric contact lens 40, specifically a prismballast toric lens, designed in accordance with the invention.

[0057]FIG. 4 shows a very complex lens design, produced in accordancewith the present invention. This complex lens includes asymmetricalthree dimensional surface components that can not be satisfactorilydesigned using conventional two dimensional methods and techniques.

[0058] Lens design using the present invention more specificallycomprises the following steps. A corneal shape of a patient is firstdetermined. A selected number of sample data points representing thecornea are provided using conventional means. A desired fittingrelationship of the lens back surface to the cornea is then specified tomeet the wearer's physiological, physical and/or optical requirements. Asimulated three dimensional surface is then defined using an algorithmto interpolate between the data points. This simulated three dimensionalsurface can be formed on a tooling insert, or directly onto a lensposterior surface, for example by using a computer driven surfacecutting tools, mills or lathes.

[0059] Next, an anterior surface of the lens is designed. Particularly,key lens thickness data points are specified to achieve the desiredclinical performance, e.g. vision correction, rotational orientation ofa toric lens and the like. Examples of such thickness data for the threelens types are shown in FIGS. 2a-2 b, FIGS. 3a-3 b, and FIG. 4. Theanterior surface of the lens is now designed by using an algorithm inconjunction with the key lens thickness data.

[0060] In certain embodiments, the lens is designed to correct or reducewavefront aberrations of a patient's eye. A wavefront aberration is thethree dimensional profile of the distance between a real light wavefront of a central spot of light and a reference surface, e.g., an idealspherical shape, as shown in FIG. 1 of U.S. Pat. No. 6,585,375, and asdescribed in Mierdel et al., “Der Ophthalmologe”, No. 6, 1997, theentire disclosures of each of which is hereby incorporated by reference.A wavefront aberration may be understood to be an optical pathdifference between an actual image wavefront and an ideal referencewavefront centered at an image point, at any point in the pupil of aneye. Methods of measuring wavefront aberration are well known to personsof ordinary skill in the art.

[0061] Briefly, and as described by Nader, N., Ocular Surgery News,“Learning a new language: understanding the terminology ofwavefront-guided ablation” (Feb. 1, 2003), an aberrometer (e.g., aninstrument that measures the aberrations of an eye) may be used tomeasure an aberrated image that leaves an eye, or may be used to measurethe shape of a grid projected onto the retina. For example, while apatient is maintaining a view on a visual fixation target, a relativelynarrow input laser beam may be directed through the pupil and focusedonto the retina of the patient's eye to generate a point-light source onthe retina. The light is reflected from the retina back through thepupil, and the wavefront of the light passing from the eye is passed toa wavefront sensor. As understood by persons of ordinary skill in theart, a wavefront can be defined as a surface that connects all fieldpoints of an electromagnetic wave that are equidistant from a lightsource. The light rays leave the eye and may pass through an array oflenses that detects the light rays' deviation. The wavefront getsdeviated or distorted by inhomogeneities in the refractive properties inthe refractive media of the eye, such as the lens, the cornea, theaqueous humor, and the vitreous humor. The resulting image is thentypically recorded by a charge coupled device (CCD) camera, for example.

[0062] The wavefront is then typically reconstructed and the deviationsare described mathematically in three dimensions. The wavefrontdeviations may be calculated, at least in part, by analyzing thedirection of the light rays. Generally, parallel light beams indicate awavefront with little, if any, aberrations, and nonparallel light beamsindicate a wavefront with aberrations that do not give equidistant focalpoints.

[0063] Typically, Zernike polynomials are used to measure or analyze theocular aberrations. Each Zernike polynomial describes a shape or athree-dimensional surface. As understood by persons of ordinary skill inthe art, Zernike polynomials are an infinite set, but in ophthalmology,the Zernike polynomials are usually limited to the first fifteenpolynomials. Second-order Zernike terms represent conventionalaberrations, such as defocus and astigmatism. Aberrations abovesecond-order aberrations are called higher-order aberrations.Higher-order aberrations typically cannot be corrected by conventionalspherocylindrical lenses. Examples of higher-order aberrations include,but are not limited to, coma, spherical aberrations, trefoil (wavefrontswith threefold symmetry), and quadrefoil (wavefront shapes with fourfoldsymmetry). Many higher-order aberrations are not symmetrical, but somehigher-order aberrations, such as spherical aberrations, may besymmetrical.

[0064] In accordance with the present invention, the wavefrontaberration of a patient's eye may be measured and analyzed to facilitateappropriate lens construction. The lenses of the present invention canthen be shaped, as discussed herein, taking into account theconfiguration or topography of the patient's corneal surface, as well asany wavefront aberrations. For example, by first shaping the lens bodyto have a posterior surface that corresponds to the corneal surfacetopography of an eye, and then shaping the lens body to correct anywave-front aberration associated with the patient's eye. Thus, a contactlens is obtained with a lens body configured to correct a wavefrontaberration of a patient's eye. Advantageously, contact lenses areprovided that may be custom-fit for a particular patient taking intoconsideration factors, such as, corneal surface topography,astigmatisms, wavefront aberrations, and variations in optical power. Inone embodiment, a contact lens is provided with a ballast, and anoptical zone including a wavefront aberration corrective surface. Thewavefront aberration corrective surface may be provided on either theanterior surface, the posterior surface, or both the anterior andposterior surfaces. Thus, in certain embodiments, the present lensescorrect or reduce higher-order wavefront aberrations. In situationswhere the higher-order wavefront aberrations are asymmetrical, thelenses are configured to substantially maintain a desired orientation tocorrect the wavefront aberrations. In some embodiments, the wavefrontaberration correction orientation is achieved by utilizing a ballast onthe lens. In other embodiments, the lens may include a plurality ofthickened regions or portions which facilitate proper orientation tocorrect or reduce a wavefront aberration.

[0065] The outcomes of the construction of posterior and anteriorsurfaces, in accordance with a method of the invention, of the threelens types are demonstrated by the three dimensional schematicrepresentations in FIGS. 5a-7 b. More specifically, FIGS. 5a, 6 a and 7a show rear surface/cornea separation of the three lens types, and FIGS.5b, 6 b and 7 b show radial thickness profiles of the three lens types.

[0066] Turning now specifically to FIGS. 7a and 7 b, the complex lensdesign is shown as smooth and substantially junctionless, despite thevaried surface topography thereof. Those of skill in the art willappreciate that this complex lens design cannot be produced usingconventional two dimensional mathematically based lens design techniquesand methods. It is further noted that the contours of the lens surfaceshown in FIG. 7b can not be produced using offset rotationally symmetriccurves and other sophisticated current design methods.

[0067] The step of providing sample data points may be accomplishedusing conventional techniques and equipment in which sample data points,for example, sagittal depths, can be designated, supplied or selected,for representing the designated surface.

[0068] As will be appreciated by those skilled in the art, the task ofmathematically representing a surface smoothly in three dimensions,given a limited number of scattered data points and specifications, canbe accomplished by many methods and for particular shapes and designspecifications. It is known that one algorithm may provide a betterdescription than another, for example by providing different degrees ofaccuracy. The present invention can be exemplified by three algorithms,which follow hereinafter, although it is recognized that the presentinvention is not limited to any particular algorithms or combinations ofalgorithms.

[0069] The step of forming the lens surface having the three dimensionalcontour may include shaping a lens using a computer driven mill or latheor other suitable cutting tool. The simulated three dimensional surfacemay be inputted in digital form into a computer driven lathe, and thelathe programmed to cut the junctionless, three dimensional surface intoa lens blank, a tooling insert (for example in cast molded lenses), or acornea (for example during laser surgery).

[0070] The central portion of an ophthalmic lens is typically referredto as the “optical zone” of the lens in that it provides the opticalcorrection. Depending on the wearer, the optical zone may be describedby a spherical conic section, or it may be another, more complicatedconfiguration, such as a toric optical zone. The present invention isespecially advantageous in design of toric contact lenses, as well aseven more complex designs.

[0071] Contact lenses having a toric surface, such as a toric opticalzone (commonly referred to as “toric contact lenses”) are commonly usedto correct refractive abnormalities of the eye relating to astigmatism.Astigmatism may be associated with other refractive abnormalities, suchas myopia (nearsightedness), and hypermetropia (farsightedness),presbyopia and the like. Toric contact lenses can be prescribed with oneor more spherical corrections.

[0072] Whereas spherical contact lenses may freely rotate on the eye,toric contact lenses typically include a ballast, or a thickened lenssection, to inhibit or reduce rotation of the lens on the eye such thatthe cylindrical axis of the toric zone remains generally aligned withthe axis of the astigmatism. The ballast provides an asymmetriccomponent to the lens that can be addressed by the present invention. Incertain embodiments, a ballast is defined by varying the anteriorsurface of the lens body. In other embodiments, a ballast is defined byvarying both the anterior surface and posterior surface of the lensbody.

[0073] Multifocal contact lenses may be provided with a varied surfacetopography to facilitate vertical lens translation. The varied surfacetopography may include a ballast, or may include another structuralfeature on the anterior surface, the posterior surface, or both theanterior surface and posterior surface of the lens, such as one or moreprotuberances or protrusions, that facilitate vertical lens translation.Examples of protuberances include ledges, ridges, lips, and ribs, amongother things. Ridges and ribs may be provided as regions of the lensbody that project anteriorly from the anterior surface of the lens body.A ledge may be provided as a region of the lens body where the lens bodyrapidly, but smoothly, transitions from a thickened region to a thinnerregion.

[0074] Vertical lens translation, as used herein, refers to the relativeup and down, or vertical, movement of the contact lens on an eye withrespect to the pupil of the eye. Thus, vertical lens translation mayrefer to changes in relative position of the contact lens with respectto the pupil of the eye caused by movement of the lens, movement of theeye, or a combination of movement of the lens and the eye.

[0075] By way of example, and not by way of limitation, a multifocallens, such as a bifocal lens, may include an optical zone with twooptical powers. Thus, the optical zone may have an inferior portion witha first optical power, and a superior portion with a second opticalpower. The inferior portion of the optical zone may have an opticalpower suitable for reading, thereby defining a reading or near zone.Typically, when the eye with the multifocal optical zone is lookingforward (e.g., towards the horizon), the reading zone will be locatedbelow or substantially below the center of the pupil of the eye, andsubstantially all of the vision correction is provided by the superiorportion of the optical zone of the lens. As the eye moves down to lookat a book, for example, the lens of the present invention will typicallyeffectively move vertically upward so that the reading zone covers atleast a portion of the pupil to provide vision correction based on theoptical power of the reading zone.

[0076] In certain embodiments, the effective upward movement of the lensmay be achieved by substantially maintaining the lens in a fixedposition as the eye rotates downward so that the pupil is covered by theinferior portion of the lens as the eye moves downward. In otherembodiments, the effective upward movement of the lens may be achievedby movement of the lens upwardly, for example, by actions imposed on thelens by one or more of the eyelids of the eye. In yet anotherembodiment, a lower eyelid may engage with a ballast or other feature onthe surface of the lens to hold the lens in a relatively fixed position.As the eye looks down, for example by rotating, the lower eyelid maymove the lens slightly downward, but the rotation of the eye isrelatively greater than the movement of the lens to cause the pupil tobe covered by at least a portion of the inferior zone of the opticalzone.

[0077] The varied surface topography of such lenses may be in the formof a ballast, which may be formed by varying the thickness or shape ofthe anterior and/or posterior surface of the lens body. In someembodiments, effective vertical lens translation is obtained bycontrolling the rate of change of lens thickness. Compared to toriccontact lenses, multifocal lenses with ballasts may have a relativelygreater rate of change in the ballast region. Thus, the multifocallenses in accordance with the present invention may have ballasts thatare configured to provide effective vertical lens translation, asdescribed above.

[0078] With particular reference to FIG. 8, the present inventionfurther includes tools or tooling inserts 112 and 113 useful for castmolding a posterior surface and an anterior surface, respectively, of anophthalmic lens. The tooling inserts 112 and 113 are adapted to beplaced in molding apparatus 115 and 116 in forming a first mold sectionor half 117 and a second mold section or half 118, each having anegative impression of a surface of the respective tooling insert. Thesurfaces of the inserts 112 and 113 are substantially smooth,junctionless three dimensional asymmetrical surfaces corresponding to adesired ophthalmic lens posterior surface and anterior surface,respectively. The mold sections or halves 117 and 118 are assembledtogether to form an assembled mold 120, which defines a lens-shapedcavity. A polymerizable/curable monomer composition is placed in thecavity and is processed, e.g., polymerized and/or cured, to form acontact lens. Such processing may be conventional and well known in theart and, therefore, needs not be described in detail. The lens isdemolded and may be subjected to conventional additional processingsteps, such as sterilization, packaging and the like.

[0079] Tool inserts and molding sections produced by such tool inserts,as described herein, are within the scope of the present invention.

[0080] In another embodiment of the invention, a method for reshapingthe cornea of an eye is provided. The method generally comprisesselecting or designating sample data points representing a correctedcorneal surface of an eye of a patient, e.g., human being, andinterpolating, using at least one algorithm, between the sample datapoints, to produce a substantially smooth, continuous, three dimensionalsurface. Preferably, sample data points from a three dimensional surfaceof the uncorrected surface of the patient's cornea are obtained and areinterpolated between using at least one algorithm to produce a smooth,substantially junctionless simulated three dimensional uncorrectedsurface. Using a conventional computer driven laser system supplied withthe simulated surface contour, and preferably the simulated uncorrectedsurface contour, the cornea is reshaped to approximate the simulatedsurface contour. In this embodiment of the invention, the method can beused with conventional corneal refractive laser surgical systems toalter the refractive capabilities of the eye by selectively ablating orreshaping the corneal stromal tissue, and in some cases, followingtemporary removal of an anterior corneal flap. The method is useful inproducing an asymmetric surface such as a corneal surface, for example,to correct astigmatism, in providing custom corneal shaping for improvedoptical correction, in providing a correction centered over the cornealapex which is often not aligned with the pupil center and the like.

[0081] The following non-limiting Examples illustrate certain aspects ofthe invention.

EXAMPLES Designing a Toric Lens Based on a Method of the PresentInvention

[0082] The steps to be employed to design a toric contact lens inaccordance with the present invention include:

[0083] (1) Determine a corneal shape.

[0084] (2) Select and represent a desired lens/cornea fittingrelationship.

[0085] (3) Specify a posterior surface including a toric optical zone.

[0086] (4) Use Algorithm X to represent the posterior surface of thelens in three dimensions.

[0087] (5) Specify center thickness of the lens.

[0088] (6) Select an optical power of the lens.

[0089] (7) Determine lens mass distribution (selected sample points).

[0090] (8) Use Algorithm X to represent the anterior surface of the lensin three dimensions, including a graphical representation.

[0091] Algorithm X can be any suitable algorithm effective forinterpolation to provide the desired simulated three dimensionalsurfaces. Three such mathematical methods using suitable algorithms usedin interpolation between data points are provided and discussed below.

Interpolation Methods

[0092] Generally speaking, a list of n data points and their values (z₁. . . z_(n))=[z(x_(i), yα)₁ . . . z(x_(n), y_(n))] is specified whichconstitutes an incomplete representation of the unknown underlyingsurface f*(x, y). Overall, an interpolating function f(x,y) is chosenfor which f(x_(i),y_(i))=z_(i), i=1 . . . , n and f→f* monotonically asn→∞.

[0093] It has been assumed that the smoothness of the underlying surfacef is generally considered to be at least C¹ (or possibly piecewise C¹),and this assumption is built into the mathematical formation.

I. The Shepard Method (Shepard 1968)

[0094] In the basic Shepard method, the interpolated value φ at anypoint (x,y) is defined by a weighted sum of the data points, where theweighting is proportional to the inverse square of the distance between(x, y) and the data points.

[0095] In its simplest form, the algorithm can be represented by theequation${\varphi ( {x,y} )} = \frac{\sum\limits_{i = 1}^{N}{h_{i}{{( {x,y} ) - ( {x_{i},y_{i},} )}}^{- 2}}}{\sum\limits_{i = 1}^{N}{{( {x,y} ) - ( {x_{i},y_{i}} )}}^{- 2}}$

[0096] where h_(i) is the ith data point, (x_(i), y_(i)) its position,and N is the number of data points.

II. The Interpolation Method (Cline and Renka, 1984)

[0097] The following is a summary description of the interpolationmethod hereinafter referred to as the CR scheme; this method isdescribed more fully in, Cline A. K. and Renka, R. J., “AStorage-efficient Method for Construction of A Thiessen Triangulation”,Rocky Mountain J. Math. 14(1), 119-139 (1984); Renka, R. J. and Cline,A. K., “A Triangle-based C¹ Interpolation Method”, Rocky Mountain J.Math. 14(1) 223-237 (1984); and Renda R. J., “Algorithm 624:Triangulation and Interpolation At Arbitrarily Distributed Points In ThePlane”; ACM Trans. Math, Software 10(4) 440-442 (1984). Each of thesePublications is incorporated in its entirety herein by reference.

[0098] The CR scheme comprises the following steps:

[0099] a. Partition the convex hull associated with the set of knowndata points {(x₁, y₁), . . . (x_(n), y_(n))} into triangles (CR Step 1).

[0100] b. Estimate the partial derivatives of the interpolating functionf (x,y) at each data point (CR Step 2).

[0101] c. For any arbitrary point (x₀,y₀) in the convex hull, the valueof the interpolating function f (x₀,y₀) can then be calculated using thedata values and partial derivatives at each of the vertices of thetriangle containing (x₀,y₀). The calculation is based on a cubic surfacecapping the triangle (CR Step 3).

Step 1. Triangulation

[0102] Let S be the set of nodes (data points) {(x₁, y₁), . . . (x_(n),y_(n))}, where n≧3 and (x_(i), y_(i))≠(x_(j), y_(j)) for i≠j. N_(i) isused to denote the node (x_(i), y_(i)). Let H be the convex hull of S.

[0103] A triangulation of S is a set of triangles T with the followingproperties: (i) each triangle contains exactly three nodes, (ii) theinterior regions of the triangles are pairwise disjoint, and (iii) everypoint in H is contained in some triangle of T.

[0104] To maximize the accuracy of Steps (ii) and (iii) above, constructa triangle that is as nearly equiangular as possible. To do this, definean arc as the undirected line segment N_(i)

N_(j), i≠j, joining two vertices of a triangle in T. An arc N_(i)

N_(j) is locally optimal if it lies on the boundary of H or if thequadrilateral defined by a pair of adjacent triangles that share nodesis not strictly convex.

[0105] The triangulation required is one in which all arcs are locallyoptical. The resulting triangulation0 is called a Thiessentriangulation, or a Delaunay triangulation. Cline and Renka (1984) givethe following algorithm for producing a Thiessen triangulation.

[0106] For each node N_(i), define the Thiessen region associated withN_(i) to be the set of points (x,y) which satisfy (x,y)−N_(i)(x,y)−N_(j) for all i≠j.

[0107] A pair of nodes N₁, N₂ are said to be Thiessen neighbours iftheir corresponding Thiessen regions share at least one point. If theregions share exactly one point, N₁ and N₂ are called weak Thiessenneighbours, if they share two or more points, they are called strongThiessen neighbours.

[0108] Connect all pairs of strong Thiessen neighbours, and arbitrarilychoose k−3 nonintersecting arcs connecting weak neighbours when k nodeslie on a common circle (k≧4).

Step 2. Estimate Partial Derivatives of the Interpolating Functionf(x,y) at each Data Point

[0109] After performing the triangulation, the next step in the CRscheme is to determine the partial derivatives of the interpolatingfunctions at each node.

[0110] The value of the following partial derivative vectors are to befound: $\begin{matrix}{D_{({x,y})} = ( {{\frac{\partial f}{\partial( {x,y} )}( {x_{1},y_{1}} )},\ldots \quad,{\frac{\partial f}{\partial( {x,y} )}( {x_{n},y_{n}} )}} )} & (1)\end{matrix}$

[0111] Such vectors minimize the L₂ norm of the linearized curvatureover H of the interpolating function f (x,y). This leads directly to theproblem of finding the value of the partial derivatives (1) whichminimize the quadrilateral functional $\begin{matrix}{{Q_{k}( {D_{x},D_{y}} )} = {\int_{P_{k}}{\{ {( \frac{\partial^{2}f}{\partial x^{2}} )^{2} + {2( \frac{\partial^{2}f}{{\partial x}{\partial y}} )^{2}} + ( \frac{\partial^{2}f}{\partial y^{2}} )^{2}} \} {x}{y}}}} & (2)\end{matrix}$

[0112] where P_(k) is the patch of triangles containing node k. Asdescribed in Renka and Cline (1984), equation (2) leads to a linearsystem $\begin{matrix}{{\frac{\partial Q_{k}}{\partial D_{x}} = 0},{\frac{\partial Q_{k}}{\partial D_{y}} = 0}} & (3)\end{matrix}$

[0113] which is solved by a block Gauss-Seidel method to recover therequired derivatives D_(x) and D_(y).

Step 3. Sampling

[0114] For any arbitrary point in the convex hull, the value of theinterpolating function can be calculated using the data values andpartial derivatives at each of the vertices of the triangle containingthe arbitrary point. The calculation is based on a cubic surface cappingthe triangle.

[0115] The previous two steps have constructed the skeleton of theinterpolating function at the known data points of the surface. In theabsence of an elementary formula for the underlying surface, themathematical description of the surface will be complete when thealgorithm representing f(x,y) returns a reasonable value for any(x,y)=(x₀,y₀)in the region of interest.

[0116] This process is a common one in interpolation and finite-elementanalysis, and therefor will not be described in detail herein. Insummary, the value of f(x₀,y₀) for some (x₀,y₀)=H is calculated by aprocedure due to Lawson (1976). On the triangle T containing (x₀,y₀),the local structure of f is represented by the cubic element F (x,y)spanning the triangle, so that f (x₀,y₀)=F (x₀,y₀). The local element Fhas the following properties:

[0117] 1. F is a true cubic (not bicubic) in each of the threesubtriangles of equal area formed by connecting the vertices to thebarycenter of the triangle containing (x₀,y₀).

[0118] 2. F is C¹

[0119] 3. On each triangle edge, N_(i)

N_(j), F is a Hermite cube interpolate of z_(i),z_(j) and theirdirectional derivatives at the endpoints N_(i) and N_(j). Furthermore,the derivative of F in the direction normal to N_(i)

N_(j) interpolates the normal derivative at N_(i) and N_(j).

[0120] The last two properties guarantee the C¹ continuity acrosstriangle borders (and hence over the whole region H), since thederivatives at any point on a triangle side are completely determined bytheir values at the endpoints of the side.

[0121] With the construction of local cubic elements F, values lyingbetween the local known data points can be determined. The surface isthus knowable at any point in the region covered by the data.

III. Interpolation Method (The Bicubic Spline)

[0122] This interpolation method, described in Dierck, P., “An Algorithmfor Surface Fitting With Spline Functions”, IMA Journal of NumericalAnalysis, v.1, pp. 267-283 (1981), calculates a smooth, bicubic splineapproximation φ (x,y) to the set of scattered data points (x_(i), y_(i),h_(i)) weights w_(i), where i=1 . . . N. The spline is given theB-spline representation $\begin{matrix}{{\varphi ( {x,y} )} = {\sum\limits_{k}{\sum\limits_{l}{c_{kl}{Q_{k}(x)}{P_{l}(y)}}}}} & (4)\end{matrix}$

[0123] where Q_(k) (x) and P₁ (y) are normalized cubic B-splines definedon an interactively calculated set of knots, and the coefficients C_(k1)are to be determined.

[0124] At the kth iteration, the current knot set is used to fit abicubic spline to the data in a least—squares sense. The residualvariance $\begin{matrix}{\theta = {\sum\limits_{i = 1}^{N}{w_{i}^{2}( {h_{i} - {\varphi_{k}( {x_{i},y_{i}} )}} )}^{2}}} & (5)\end{matrix}$

[0125] is then calculated. If θ is greater than a user-specifiednon-negative limit S, the knot set is refined by adding extra knots inregions where the fit is most poor (that is, where θ is largest) toproduce the knot set for the (k+1)th iteration. After many suchiterations, the criterion θ≦S is satisfied, the set of knots isaccepted.

[0126] The above-noted publication by P. Kierck is hereby incorporatedin its entirety herein by reference.

[0127] The final approximation to the surface is then calculated as thesolution to the optimization problem of finding the coefficients inequation (4) that minimizes a global smoothness measure subject to theconstraint θ<S.

[0128] Although there has been hereinabove described specific ophthalmiclenses having a junctionless, three dimensional surface, and methods forproducing same, in accordance with the present invention, for thepurpose of illustrating the manner in which the present invention may beused to advantage, it should be appreciated that the invention is notlimited thereto.

[0129] While this invention has been described with respect to variousspecific examples and embodiments, it is to be understood that theinvention is not limited thereto and that it can be variously practicedwithin the scope of the following claims.

What is claimed is:
 1. A contact lens comprising: a lens body includinga silicone hydrogel and structured and adapted to be located on an eyeand having an anterior surface and a generally opposing posteriorsurface, wherein at least one of the anterior surface and the posteriorsurface is a substantially smooth, junctionless three dimensionalasymmetrical surface, and the contact lens has a varied surfacetopography with at least one contour that defines a substantiallyjunctionless varying radial thickness of the contact lens, the variedsurface topography facilitating at least one of lens comfort, lensorientation, vertical lens translation, and lens stabilization when thecontact lens is placed on a surface of a cornea of an eye.
 2. Thecontact lens of claim 1 wherein the posterior surface is a substantiallysmooth, junctionless three dimensional asymmetrical surface.
 3. Thecontact lens of claim 1 wherein the anterior surface is a substantiallysmooth, junctionless three dimensional asymmetrical surface.
 4. Thecontact lens of claim 1 wherein both the anterior surface and theposterior surface are substantially smooth, junctionless threedimensional asymmetrical surfaces.
 5. The contact lens of claim 1,wherein the contact lens has a varied anterior surface defining aballast.
 6. The contact lens of claim 1, wherein the lens body has avaried anterior surface and a varied posterior surface defining aballast.
 7. The contact lens of claim 1, wherein the lens body includesa toric surface.
 8. The contact lens of claim 1, wherein the posteriorsurface of the lens body is structured to approximate a curvature of acorneal surface when the lens body is placed on a surface of a cornea ofan eye.
 9. The contact lens of claim 1, wherein the lens body includes amultifocal optical zone.
 10. The contact lens of claim 1, wherein thelens body is configured to correct or reduce a wavefront aberration of apatient's eye.
 11. A contact lens comprising: a lens body including ahydrophilic silicone polymer component, the lens body having a toricsurface, and a varied surface topography with at least one contour thatdefines a substantially junctionless varying radial thickness of thecontact lens, the varied surface topography facilitating at least one oflens comfort, lens orientation, vertical lens translation, and lensstabilization when the contact lens is placed on a surface of a corneaof an eye.
 12. The contact lens of claim 11, wherein the lens bodycomprises a silicone hydrogel.
 13. The contact lens of claim 11, whereinthe hydrophilic silicone polymer component includes units from at leastone monomer selected from a group consisting of silicon-containingmonomers for polymerization into hydrophilic silicone polymers andmixtures thereof.
 14. The contact lens of claim 13, wherein the at leastone monomer is selected from the group consisting of siloxanes,silicon-containing acrylates, silicon-containing methacrylates, andmixtures thereof.
 15. The contact lens of claim 11, wherein the lensbody is structured to correct an astigmatism of an eye.
 16. The contactlens of claim 11, wherein the lens body includes a ballast.
 17. Thecontact lens of claim 11, wherein the varied surface topography isprovided on an anterior surface of the contact lens.
 18. The contactlens of claim 11, wherein the lens body includes a substantially smooth,junctionless three dimensional asymmetrical posterior surface.
 19. Thecontact lens of claim 11, wherein the lens body includes a substantiallysmooth, junctionless three dimensional asymmetrical anterior surface.20. The contact lens of claim 11, wherein the lens body includes aposterior surface structured to approximate a curvature of a cornealsurface when the lens body is placed on a surface of a cornea of an eye.21. The contact lens of claim 20, wherein the posterior surface isstructured to maintain a substantially uniform distance between theposterior surface of the lens body and the corneal surface when the lensbody is placed on a surface of a cornea of an eye.
 22. The contact lensof claim 11, wherein the lens body is configured to correct or reduce awavefront aberration of a patient's eye.
 23. A contact lens comprising:a lens body structured and adapted to be located on an eye and having ananterior surface and a generally opposing posterior surface, wherein atleast one of the anterior surface and the posterior surface is asubstantially smooth, junctionless three dimensional asymmetricalsurface, and the contact lens has a varied surface topography defining aballast and at least one contour that defines a substantiallyjunctionless varying radial thickness of the contact lens, the variedsurface topography facilitating at least one of lens comfort, lensorientation, vertical lens translation, and lens stabilization when thecontact lens is placed on a surface of a cornea of an eye.
 24. Thecontact lens of claim 23, wherein the lens body includes a hydrophilicsilicone polymer component.
 25. The contact lens of claim 24, whereinthe lens body includes a silicone hydrogel.
 26. The contact lens ofclaim 23, wherein the lens body includes a toric surface.
 27. Thecontact lens of claim 23, wherein the posterior surface is asubstantially smooth, junctionless three dimensional asymmetricalsurface.
 28. The contact lens of claim 23, wherein the anterior surfaceis a substantially smooth, junctionless three dimensional asymmetricalsurface.
 29. The contact lens of claim 23, wherein both the anteriorsurface and the posterior surface are substantially smooth, junctionlessthree dimensional asymmetrical surfaces.
 30. The contact lens of claim23, wherein the lens body is configured to correct or reduce a wavefrontaberration of a patient's eye.
 31. A contact lens comprising: a lensbody including a hydrophilic silicone polymer component, the lens bodyhaving a multifocal optical zone, and a varied surface topography withat least one contour that defines a substantially junctionless varyingradial thickness of the contact lens, the varied surface topographyfacilitating at least one of lens comfort, lens orientation, verticallens translation, and lens stabilization when the contact lens is placedon a surface of a cornea of an eye.
 32. The contact lens of claim 31,wherein the lens body comprises a silicone hydrogel.
 33. The contactlens of claim 31, wherein the hydrophilic silicone polymer componentincludes units from at least one monomer selected from a groupconsisting of silicon-containing monomers for polymerization intohydrophilic silicone polymers and mixtures thereof.
 34. The contact lensof claim 33, wherein the at least one monomer is selected from the groupconsisting of siloxanes, silicon-containing acrylates,silicon-containing methacrylates, and mixtures thereof.
 35. The contactlens of claim 31, wherein the lens body includes a ballast.
 36. Thecontact lens of claim 31, wherein the varied surface topography isprovided on an anterior surface of the contact lens.
 37. The contactlens of claim 31, wherein the lens body includes a substantially smooth,junctionless three dimensional asymmetrical posterior surface.
 38. Thecontact lens of claim 31, wherein the lens body includes a substantiallysmooth, junctionless three dimensional asymmetrical anterior surface.39. The contact lens of claim 31, wherein the lens body includes aposterior surface structured to approximate a curvature of a cornealsurface when the lens body is placed on a surface of a cornea of an eye.40. The contact lens of claim 39, wherein the posterior surface isstructured to maintain a substantially uniform distance between theposterior surface of the lens body and the corneal surface when the lensbody is placed on a surface of a cornea of an eye.
 41. The contact lensof claim 31, wherein the lens body includes a bifocal optical zone. 42.The contact lens of claim 31, wherein the lens body includes a variedanterior surface and a varied posterior surface defining a ballast. 43.The contact lens of claim 31, wherein the lens body is configured tocorrect or reduce a wavefront aberration of a patient's eye.